hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/InternalScan.java

   1 /**
   2  *
   3  * Licensed to the Apache Software Foundation (ASF) under one
   4  * or more contributor license agreements.  See the NOTICE file
   5  * distributed with this work for additional information
   6  * regarding copyright ownership.  The ASF licenses this file
   7  * to you under the Apache License, Version 2.0 (the
   8  * "License"); you may not use this file except in compliance
   9  * with the License.  You may obtain a copy of the License at
  10  *
  11  *     http://www.apache.org/licenses/LICENSE-2.0
  12  *
  13  * Unless required by applicable law or agreed to in writing, software
  14  * distributed under the License is distributed on an "AS IS" BASIS,
  15  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  16  * See the License for the specific language governing permissions and
  17  * limitations under the License.
  18  */
  19 package org.apache.hadoop.hbase.regionserver;
  20
  21 import java.io.IOException;
  22
  23 import org.apache.hadoop.hbase.HBaseInterfaceAudience;
  24 import org.apache.hadoop.hbase.classification.InterfaceAudience;
  25 import org.apache.hadoop.hbase.client.Get;
  26 import org.apache.hadoop.hbase.client.Scan;
  27
  28 /**
  29  * Special scanner, currently used for increment operations to
  30  * allow additional server-side arguments for Scan operations.
  31  * <p>
  32  * Rather than adding new options/parameters to the public Scan API, this new
  33  * class has been created.
  34  * <p>
  35  * Supports adding an option to only read from the MemStore with
  36  * {@link #checkOnlyMemStore()} or to only read from StoreFiles with
  37  * {@link #checkOnlyStoreFiles()}.
  38  */
  39 @InterfaceAudience.LimitedPrivate(HBaseInterfaceAudience.COPROC)
  40 public class InternalScan extends Scan {
  41   private boolean memOnly = false;
  42   private boolean filesOnly = false;
  43
  44   /**
  45    * @param get get to model scan after
  46    */
  47   public InternalScan(Get get) {
  48     super(get);
  49   }
  50
  51   /**
  52    * @param scan - original scan object
  53    * @throws IOException
  54    */
  55   public InternalScan(Scan scan)
  56       throws IOException
  57   {
  58     super(scan);
  59   }
  60
  61   /**
  62    * StoreFiles will not be scanned. Only MemStore will be scanned.
  63    */
  64   public void checkOnlyMemStore() {
  65     memOnly = true;
  66     filesOnly = false;
  67   }
  68
  69   /**
  70    * MemStore will not be scanned. Only StoreFiles will be scanned.
  71    */
  72   public void checkOnlyStoreFiles() {
  73     memOnly = false;
  74     filesOnly = true;
  75   }
  76
  77   /**
  78    * Returns true if only the MemStore should be checked.  False if not.
  79    * @return true to only check MemStore
  80    */
  81   public boolean isCheckOnlyMemStore() {
  82     return (memOnly);
  83   }
  84
  85   /**
  86    * Returns true if only StoreFiles should be checked.  False if not.
  87    * @return true if only check StoreFiles
  88    */
  89   public boolean isCheckOnlyStoreFiles() {
  90     return (filesOnly);
  91   }
  92 }